Published: Thu, July 12, 2018
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Fossil In Argentina Suggests Giant Dinosaurs Evolved Earlier Than Previously Thought

Fossil In Argentina Suggests Giant Dinosaurs Evolved Earlier Than Previously Thought

According to one of the researchers, "As soon as we found it, we realized it was something different". However, the earliest examples of this group were small, bipedal creatures.

"But with this discovery we can see the first steps toward gigantism occurred 30 million years before the giants dominated practically the entire planet". "It was at least twice as large as the other herbivores of the time".

The remains of a 200-million-year old species, baptized Ingenia prima, was discovered in the Balde de Leyes dig site in San Juan province, 1,100km (680 miles) west of the Argentine capital, Buenos Aires.

The creature has been dubbed "Ingentia prima" (Latin for "first giant"), and it's been classed as a sauropodomorph, the group that would later evolve into the enormous sauropods.

Dinosaurs first appeared earlier in the Triassic Period, roughly 230 million years ago. The authors say many of these adaptations were not specific to gigantism, instead allowing for greater mobility as I. prima moved across the Triassic landscape.

Cecilia Apaldetti, from the National University of San Juan, and colleagues analyzed the fossils along with three other specimens of closely related but previously documented dinosaur called Lessemsaurus sauropoides. The lengthy neck and tail belonged to the sauropod family of dinosaurs.

The dinosaur - named Ingentia prima, meaning "the first giant" - was the size of a double-decker bus, weighed about 10 tonnes, and lived around 210 million years ago during the Triassic Period.

Excavators found several vertebrae from the neck and tail as well as fore and hind leg bones.

What is really unexpected is that the lessemsaurids achieved their huge bodies independently of the enormous sauropods like Brontosaurus and Diplodocus, which did indeed evolve later during the Jurassic.

But unlike their more recent counterparts they stood on bent legs and had bones that grew thick through accelerated bursts - showing there is more than one way to "make" a giant dinosaur.

"These pneumatic cavities indicate that this new species had highly developed air sacs and a very efficient breathing system, similar to what happens in modern birds, which also helped it to keep its body cool despite its large size". At the end of the Triassic period it was a type of savannah. These eventually evolved into the four-legged creatures that became the largest animals that ever walked the land.

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